能少女叶洛意外与九王爷沧澜夜绑定契约，拥有了强行召唤出九王爷的能力，也发现这个位高权重的神秘九王爷竟然拥有人形与半妖两种形态。叶洛与沧澜夜围绕着契约斗智斗勇，也在结盟过程中逐渐相知相爱，然而沧澜夜为了不让半妖力量因契约而失控，决定远离叶洛，压制失控力量，二人的关系也迎来新的危机。

Supernatural girl Ye Luo accidentally forms a contract with the enigmatic ninth lord, Cang Lanye, who shifts between humanoid and half-demon forms. As their reluctant partnership deepens into love, Cang Lanye must distance himself to control his unstable powers, putting their bond to the ultimate test.